Bridge abutment disease treatment method for highway bridge crossing existing railway

The invention discloses an abutment disease treatment method for a highway bridge crossing an existing railway, which comprises the following steps of: in the treatment process, hoisting a bridge body of the highway bridge to the existing highway to be placed, dismantling partial abutment which has diseases and affects the safety of the existing railway, constructing a cross beam on a pile foundation, and utilizing the railway skylight time to construct the bridge abutment. And a prefabricated plate girder and the girder body are hoisted to the cross beam, the plate girder is located on the demolished bridge abutment, finally bridge deck pavement is constructed, and renovation of the damaged highway bridge is completed. According to the method, the pile foundation can be constructed before the bridge abutment is dismantled, operation of the highway bridge is not affected, when the bridge abutment is dismantled, only parts which have diseases and affect safety of an existing railway need to be dismantled, dism